nfsd: fix spurious EACCESS in reconnect_path()

[safe/jmp/linux-2.6] / fs / nfsd / nfsfh.c

diff --git a/fs/nfsd/nfsfh.c b/fs/nfsd/nfsfh.c
index c7b0fda..f45451e 100644 (file)
--- a/fs/nfsd/nfsfh.c
+++ b/fs/nfsd/nfsfh.c
@@ -176,9 +176,24 @@ static __be32 nfsd_set_fh_dentry(struct svc_rqst *rqstp, struct svc_fh *fhp)
        if (IS_ERR(exp))
                return nfserrno(PTR_ERR(exp));
 
-       error = nfsd_setuser_and_check_port(rqstp, exp);
-       if (error)
-               goto out;
+       if (exp->ex_flags & NFSEXP_NOSUBTREECHECK) {
+               /* Elevate privileges so that the lack of 'r' or 'x'
+                * permission on some parent directory will
+                * not stop exportfs_decode_fh from being able
+                * to reconnect a directory into the dentry cache.
+                * The same problem can affect "SUBTREECHECK" exports,
+                * but as nfsd_acceptable depends on correct
+                * access control settings being in effect, we cannot
+                * fix that case easily.
+                */
+               current->cap_effective =
+                       cap_raise_nfsd_set(current->cap_effective,
+                                          current->cap_permitted);
+       } else {
+               error = nfsd_setuser_and_check_port(rqstp, exp);
+               if (error)
+                       goto out;
+       }
 
        /*
         * Look up the dentry using the NFS file handle.
@@ -215,6 +230,14 @@ static __be32 nfsd_set_fh_dentry(struct svc_rqst *rqstp, struct svc_fh *fhp)
                goto out;
        }
 
+       if (exp->ex_flags & NFSEXP_NOSUBTREECHECK) {
+               error = nfsd_setuser_and_check_port(rqstp, exp);
+               if (error) {
+                       dput(dentry);
+                       goto out;
+               }
+       }
+
        if (S_ISDIR(dentry->d_inode->i_mode) &&
                        (dentry->d_flags & DCACHE_DISCONNECTED)) {
                printk("nfsd: find_fh_dentry returned a DISCONNECTED directory: %s/%s\n",